Prepond

Prepond
x = 3, y = 3, rule = B3/S23 bo$2o$2bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
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Pattern type	Tetraplet
Number of cells	4
Bounding box	3 × 3
Static symmetry	Unspecified
Discovered by	Unknown
Year of discovery	Unknown
Rules Outer-totalistic rules B3/S23 – unknown # of rules Unknown
Pattern files RLE raw RLE code

The prepond is an predecessor of the pond. It is important because it makes about 54% of the ponds that doesn't appear in any other Life-like rules (because, for some reason, the Prepond only occurs in the Game of Life). It dies out at HighLife, which is the reason these 54% just aren't there, making the pond almost half as common.